Is an asteroid really heading for Earth? This is what Nasa has to say

The chances of an asteroid crashing into Earth have just doubled after scientists reassessed the path of one named 2024 YR4.

The enormous chunk of space rock orbiting the Sun was flagged as having a possible collision course with our planet at the end of 2024.

But now scientists have raised the risk level and are monitoring it closely to see if this is likely to change again.

Nasa’s Asteroid Watch issued a new post on X warning the “impact probability with Earth has increased”.

We take a look at what this means and if we should be braced for impact.

Is an asteroid really heading towards Earth?

Asteroid 2024 YR4 was first spotted on 27 December last year by astronomers working at Nasa-funded Asteroid Terrestrial-impact Last Alert System (Atlas) telescope in Rio Hurtado, Chile.

It had a close approach with Earth on 25 December, 2024, which is why it became bright enough to be detected in asteroid surveys.

It is estimated to be around 40 to 90 metres (130 to 300 feet) in size, based on measurements of the asteroid’s brightness.

To get a better idea of its size, scientists will need to use thermal infrared observations, radar observations or imagery from a spacecraft which could closely approach the asteroid.

After it’s discovery, Nasa’s Jet Propulsion Laboratory (JPL) and Centre for Near Earth Object Studies (CNEOS) began monitoring it and identified the possibility it may hit Earth on 22 December, 2032.

As more observations were made, scientists were able to more accurately predict the risk of it colliding with Earth.

And on 27 January this year, the impact probability had increased to more than 1 per cent which is an important threshold.

This meant it had now reached a rating of three on the Torino scale (a measurement of potential Earth impact events), which is quite uncommon and the highest rating since the asteroid Apophis was discovered in 2004.

When an asteroid is bigger than 10 metres and has a greater than 1 perc ent chance of hitting Earth within the next 20 years, officials activate the International Asteroid Warning Network (IAWN).

IAWN’s steering committee met on 4 February this year in Vienna, Austria to discuss the asteroid.

Since then, the risk of it hitting Earth has been upgraded again from 1 per cent to 2.3 per cent.

In a post on X on 7 February Nasa Asteroid Watch stated: “While still an extremely low possibility, asteroid 2024 YR4’s impact probability with Earth has increased from about 1 per cent to a 2.3 per cent chance on Dec. 22, 2032.

“As we observe the asteroid more, the impact probability will become better known.”

While still an extremely low possibility, asteroid 2024 YR4's impact probability with Earth has increased from about 1% to a 2.3% chance on Dec. 22, 2032. As we observe the asteroid more, the impact probability will become better known. More: https://t.co/VWiASTMBDi pic.twitter.com/Z1mpb4UPaC

— NASA Asteroid Watch (@AsteroidWatch) February 7, 2025

In the unlikely event 2024 YR4 does hit the Earth in 2032, CNEOS estimates it would be at a high velocity, roughly 38,000 miles per hour.

This could cause blast damage as far as 30 miles from the impact site, according to IAWN. 

At present, the possible locations where Nasa estimates it may hit Earth are areas over the eastern Pacific Ocean, northern South America, the Atlantic Ocean, Africa, the Arabian Sea and South Asia.

However, it is important to note that a 2.3 per cent chance of the asteroid colliding with Earth means there is also a 97.7 per cent chance it will not make impact.

2024 YR4 is currently about 30 million miles from Earth and moving farther away on its outbound path around the Sun.

It will continue its orbit around the Sun and is expected to return closer to Earth again in 2028.

In the meantime, it is being tracked with several telescopes, including the Magdalena Ridge Observatory in New Mexico, the Danish Telescope, and the Very Large Telescope in Chile.

And it should remain possible to reserve it until early April this year, when it become too faint to be detected from the ground and space-based infrared telescopes will be needed.

How often do asteroids hit Earth?

According to Nasa, Earth is bombarded with more than 100 tons of dust and sand-sized particles every day.

About once a year, an asteroid the size of a car hits Earth’s atmosphere, creates a fireball and burns up before reaching the surface.

Every 2,000 years or so, a meteoroid the size of a football field hits Earth and causes significant damage to the area.

Once every few million years, an object large enough to threaten Earth’s civilisation comes along.

Impact craters on Earth, the moon and other planetary bodies are evidence of these occurrences.

Space rocks smaller than about about 82 feet will usually burn up as they enter the Earth’s atmosphere and cause little or no damage.

If anything larger than 82 feet but smaller than half a mile were to hit Earth, it would be likely to cause local damage to the impact area.

And Nasa believes anything larger than half a mile could have worldwide effects.